1. Field of the Invention
The invention relates to a power steering system, in particular for motor vehicles. The power steering system includes a steering valve, for controlling pressure medium for a servomotor, has two inlet seat valves and two outlet seat valves, each with one closing body. The closing bodies of the outlet seat valves are actuatable by an actuating device as a function of the rotary motion of a steering-wheel shaft connected to an input member of the steering system. The closing bodies of the inlet seat valves are hydraulically pressure balanced with reference to a pressure of a pressure source, and by the force of locking springs they keep the inlet seat valves closed in the neutral position of the steering valve. Each locking spring is supported at one end on a closing body of one of the inlet seat valves and on the other by the actuating device. The outlet seat valves are open in the neutral position of the steering valve. The effective cross section of the closing bodies of the outlet seat valves is smaller than the effective cross section of the closing bodies of the inlet seat valves.
2. Brief Description of the Prior Art
One such power steering system is known from German Patent Disclosure DE 43 03 854. In an exemplary embodiment of this known power steering system, a rack-type power steering system is described. The actuation of the steering valve is done by a pivoting motion of the pinion. The inlet seat valves and the outlet seat valves are disposed such that their axes are substantially at right angles to the axis of the pinion. The valves are disposed in a lower region of the pinion, below the rack. In motor vehicles, there is often only a very constricted space available in this region of the power steering system.